1. Technical Field
The present invention relates to fractional frequency reuse methods and systems, and more particularly to dynamic and configuration based fractional frequency reuse methods and systems.
2. Description of the Related Art
In general, the concept of fractional frequency reuse (FFR) entails allocating all available partitions of a frequency band to service wireless users near the center of a cell while restricting transmission to users near the edges of a cell to only a fraction of the available band. FFR configurations alleviate interference experienced by users of neighboring sectors of different cells. Various methods for assigning frequency partitions within an FFR framework have been developed.
One such method assigns each sector of a cell with a priority on a set of frequency partitions. Here, partitions to which a sector holds a higher priority are utilized for data transmission in the sector and, over time, data transmission in the sector is gradually expanded to frequency partitions to which the sector holds lower priorities. In other methods, arbitrary physical resource unit assignment is permitted and instantaneous channel gain is assumed for the utility computations. In addition, FFR schemes have been proposed in which the transmission power on each frequency partition is dynamically adjusted. However, arbitrary transmission power on each frequency partition is permitted. In these methods, complicated derivative computation is employed.